You can use Kerberos to provide strong authentication between Vservers and NFS clients to ensure secure NFS communication.
Beginning with version 3, NFS supports generic security services for RPC (RPCSEC_GSS), which enables the use of Kerberos 5. Kerberos provides strong secure authentication for client/server applications. Authentication provides verification of a user's or process's identity to a server. In the Data ONTAP environment, Kerberos provides authentication between Vservers and NFS clients.